This invention relates to reinforced soil structures, and it is particularly concerned with a method of and an apparatus for securing flexible polymeric strips to a facing for such a structure.
The technique of using polymeric strips in compacted granular fill behind a lightweight reinforced concrete facing is well known, and several ways of connecting the strips to the facing have been employed.
The present invention provides an assembly for use in reinforcing a soil structure comprising a polymeric strip secured to a facing by attachment means, characterised in that the attachment means comprise an elongate attachment member about which the strip is circumflected, and the facing comprises two or more blocks defining a cavity for receiving and retaining the member and a portion of the circumflected strip. The location of the attachment member within the facing serves to distribute more uniformly the load imposed on the facing by the strip. To improve its resistance to corrosion, the attachment member is preferably formed from non-metallic material.
Preferably, connecting means, which may be located in the cavity, are provided for interlinking the blocks. The connection means can be used to facilitate interlinking of the blocks, and also it may serve as a shear key between the blocks to resist shearing forces imposed on the facing when it is incorporated in a reinforced soil structure. The connection means may be provided integrally with one or more of the blocks, or as a separate element. Alternatively, the connection means and the attachment member may be integrally formed. The connection means may be formed from a non-metallic material.
In the preferred embodiment the cavity comprises a first recess disposed orthogonally to a second recess, the member is received and retained in the first recess and the depth of the first recess may be greater than that of the second recess to form a lip therebetween. The lip supports the adjacent portion of the attachment member to reduce substantially the bending moment imposed by the strip on the attachment member. Preferably the first recess and the lip are shaped to receive the attachment member and the circumflected portion of the strip. The attachment member may be held in position abutting the lip by the connection means. Preferably, the first recess is arranged laterally, and the second recess is disposed centrally, of the blocks.
The invention also provides a method of securing a polymeric strip of a reinforced soil structure to a facing therefor comprising a plurality of blocks, characterised by the steps of providing an elongate attachment member, circumflecting the strip about the member, providing two or more facing blocks defining a cavity for receiving the attachment member and a portion of the circumflected strip, and sandwiching the attachment member and the portion of the strip between the blocks in the cavity thereby to secure the strip relative to the facing.
Preferably a plurality of cavities and associated attachment members are provided, and one or more anchoring members are disposed in the soil structure, the method including the step of alternately circumflecting a continuous strip around an attachment member and an anchoring member.
A clear understanding of the invention will be gained from the following detailed description of embodiments thereof, given by way of example only, with reference to the accompanying drawings.